Method of sealing leaks in sub-surface sewer pipe



A. T. DOUSE METHOD OF SEALING LEAKS IN SUB-SURFACE SEWER PIPE Filed Jan. 20, 1959 FIG.3

INVEN TOR. ARTHUR T. DOUSE fi w ATTORNEY United States Patent 9 METHOD OF SEALING LEAKS IN SUB-SURFACE SEWER PIPE Arthur T. Douse, Fort Lauderdale, Fla. Application January 20, 1959, Serial No. 787,983

3 Claims. (Cl. 138-97) This invention relates to a method of repairing external leaks in sub-surface sewer lines.

In certain cities and other areas throughout the United States, concrete pipe has been employed to conduct sewerage through the conventional pump stations and at spaced apart points along the line of the pipe, there has been provided manholes for the entry and inspections of the sewer line. As a result of ground settlement, vibration due to trucks and other heavy vehicles, and for other miscellaneous causes, the usual bell and spigot joints in the pipes are disrupted and permit the entry of subsurface water to enter the pipe line and cause the pumps within the pumping stations to function for abnormal lengths of time. The area of south Florida consists mainly of sand and rough aggregate and the normal water level within the ground is substantially close to a street surface and, since the pipe line is laid into the ground at varying depths, the surrounding sub-surface water flows through any joint or other break in the pipe to mix with the sewerage as it flows to the pumping or lift stations. Heretofore, to repair these leaks it has been necessary to first determine the point of leak and then excavate through the street level to the point of leak, creating objectional situations from the standpoint of traific and the inconvenience of adjacent property owners. The purpose of this invention is to facilitate the location and the repair of the leaks with a minimum of effort and time and the piercing of the street surface at one or more points forming a relatively small access opening or openings.

Other objects and advantages of the invention will be more clearly apparent during the course of the following description.

Referring to the drawings:

Figure 1 is a sectional view taken transversely through the sewer pipe and illustrating the initial method of forming a cavity around the pipe at the point of leak,

Figure 2 is a similar view illustrating the method of forcing a sealing compound or other mixture around the leak in the pipe and,

Figure 3 is a longitudinal section illustrating the pipe joint and the encasing seal.

Referring specifically to the drawings, the numeral 5 designates the usual surface of a street or roadway resting upon a ground area 6. Disposed within the ground, is a sewer line embodying the usual concrete pipe sections 7 and 8. The pipe 8 is provided with the usual bell end 9 into which the spigot end of the pipe 7 is engaged and normally sealed with respect to the bell end 9. As before pointed out, the usual access manholes have been provided, usually spaced along the roadway at points approximately 400 feet apart. The manholes (not shown) are common practice in sewerage disposal lines.

When a leak occurs in the joint between the pipe sections 7 and 8 or at some point intermediate the length of the pipes, due to numerous causes, such as the settling of the ground or vibration from traflic. The leak is determined first by an inspection at the lift station, where the lift pumps are required to run an unusual length of 'ice by entry of a workman into a manhole and, by shoving a detecting mechanism through the pipe from the manhole, is able to accurately pin-point the leak. Measuring means carried by the detecting mechanism and, when the leak is observed by either visual or other means, the

measuring device determines at what length in the line the leak occurs. It may be necessary that the detecting mechanism be progressively moved from one manhole to another, since it is not possible to tell from the operation of the pumps, at which point in the .lines the leak occurs. With the leak having been located, the measuring device is then extended from the manhole along the surface of the street and the point marked, indicating that a leak occurs at that point in the pipe below the surface. With the point of leak actually pin-pointed, either one or more apertures of relatively small diameter are cut through the street surface 5. These apertures may be directly over the longitudinal center of the pipe line or it may be to one side or possibly both sides, as clearly shown in Figure 1. Jetting devices are then progressively forced downwardly through the apertures 10, forcing a hole progressively down through the ground to the point or points adjacent to the pipe line. This jetting action is performed by forcing water under pressure downwardly through the pipes 11, causing the displaced soil to flow upwardly alongside the pipes 11 and out of the apertures 10. When the jet pipes 11 have reached the point adjacent to the pipe line, the jetting action is continued, washing the soil away from the pipe throughout its diameter and creating a cavity 12. Aggregates that are sufficiently small will wash into the leaking joint and be lodged therein to initially stop the flow of water. Now, with the cavtiy 12 being formed around the joint of the pipes, pipes 13 are engaged downwardly through the aperture 10 to the point where it terminates within the cavity 12. Fluent cement is then forcibly pumped downwardly through the pipes 13 or 11 by pump devices, not shown, completely filling the cavity 12 and filling the point of leak within the bell end 9 of the pipe line and also completely encasing the bell end of the pipe, such pressurized cement being forced into the point of leak. In cases where the leak has been created by a settling of the ground, the pressure created by the cement being pumped into the cavity is suflicient to elevate and properly align the pipes similar to the conventional mud-jack and also completely sealing the same against the infiltration of sub-surface water. As shown in Figure 2, two pipes 13 have been forced downwardly through the preformed opening by the jet pipes 11 such serving to assure that the joint of the pipe will be fully encased and possibly to assure that the pipe will be properly elevated to its original alignment. The pipes 13 function in a manner similar to the conventional mudjacks however, it may be satisfactory to form a single opening 14 to the point of the pipe line, such being satisfactory With the relatively small diameter concrete pipes. With the cavity 12 being completely filled with the cement, the pipes 13 or 11 are withdrawn and any soil that has been washed upwardly through the apertures 10, is again forced downwardly into the openings created by the pipes 11 in the jetting action after which, the apertures 10 are closed. The procedure is substantially identical at points along the length of the pipe where a leak may occur.

In certain situations, the break in the sewer pipe is of such size that the aggregates will flow entirely therethrough and have no effective sealing function. In cases of this type, it would mean that when the cement is forced downwardly, it would also flow through the break in the pipe. Such a situation would be objectionable. It now becomes necessary where the leak is too large, to insert within the pipe at the point of leak an inflatable balloon that is of normal less diameter than thefdiameter of the pipe. When the balloon, indicated in dotted lines at 15, in Figure 3 is disposed at the point of the leak, the balloon is inflated, forcing its side walls into firm overlying engagement with the interior surface of the sewer pipe to effectively seal the leak. Now, when the cement is forced downwardly, it will flow into the break of the pipe and be stopped by the balloon. The balloon is left in the pipe for a predetermined length of time to permit the cement to partially harden and is then deflated and withdrawn by an operator in an adjacent manhole. The balloon is only employed where the break in the pipe isof such proportions that it cannot be initially filled with the aggregates from the soil.

It will be apparent from the foregoing that a very novel and simplified means has been provided for quickly and easily locating, exposing and repairing a sewer line leak at a minimum cost and at little or no interruption to street traffic or inconvenient to adjacent property owners. The equipment necessary is extremely simple and the entire location of the leak and its repair may be conducted in a minimum of time without destroying a relatively large surface of the roadway. The method of repair is economical to perform and is most effective and substantially permanent and avoids the necessity of expensive and inconvenient excavations.

It is to be understood that the invention is not limited to the precise construction shown, but that changes are contemplated as readily fall within the spirit of the invention as shall be determined by the scope of the subjoined claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. The hereindescribed method of repairing a leak in sub-surface sewer pipes that comprises the steps of forming an aperture in the surface above the sewer pipe, in-

serting a pipe progressively downwardly through the aperture to a point adjacent the point of leak by means of a high pressure jet stream of water discharging from the inserted pipe whereby soil will be washed away to escape upwardly alongside of the inserted pipe and to progressively create a cavity for the full circumference of the sewer pipe at the point of leak, stopping the flow of water through the inserted pipe and then pumping a fluent sealing material downwardly through the inserted pipe to completely fill the cavity and to encase the sewer pipe at the point of leak.

2. The method as recited in claim 1 wherein the fluent sealing material is composed of a mixture of cement and water.

3. The method of repairing leaks in sub-surface sewer pipes after the point of leak has been determined, that comprises the steps of forming an opening in the surface of the ground, inserting a pipe downwardly through the opening and jetting a high pressure stream of water downwardly toward the sewer pipe in the location of the leak to wash away the soil in the area of the leak and to form a cavity in the ground for the entire circumference of the pipe, stopping the fiow of water through the inserted pipe and then pumping fluent cement downwardly through the inserted pipe to completely till the cavity and to encase the pipe in the area of the leak, the leak in the sewer pipe being initially closed by an in flatable balloon that is inserted into the sewer pipe longitudinally to be inflated into sealingcngagement'with the inner area of the sewer pipe at the point of leak and to prevent the flow of external Water and the fluent cement through the leak into the sewer pipe.

References Cited in the file of this patent UNITED STATES PATENTS 1,404,353 Ellis Jan. 24, 1922 1,925,538 Knapp Sept. 5, 1933 2,079,518 McQuiston May 4,1937 

